The applicant, a participant in the current Herpetic Eye Disease Study (HEDS), proposes to be a Regional Center in Phase II of the Herpetic Eye Disease Study. Phase II will consist of two prospective randomized, double-masked clinical trials and a study of the triggers for the recurrence of ocular herpetic disease. The first trial, HEDS-EKT, will compare acyclovir to placebo for the prevention or delay of subsequent stromal keratitis or iritis in patients with active herpetic epithelial keratitis. The second, HEDS-APT, will compare acyclovir to placebo for prolonging the tine to recurrence of herpetic eye disease in patients with an episode of any herpetic eye disease in the past year and who have been free of disease and off all treatment for at least the past month. The triggers study, RFS (Recurrence Factor Study) will obtain data by questionnaire on stress, trauma, and other potential triggers for recurrence of herpetic disease for correlation with recurrence date from the two clinical trials. As a Regional Center, the applicant will be responsible for entering patients in the two clinical trials, treating and following them according to protocol; entering consenting randomized patients into the RFS study; coordinating and overseeing the participation of 8 additional participating local sites in the APT and EKT trials, and the RFS study; and participating in the governance of HEDS via participation on the Executive Committee.